Aperture 3 includes a neat font called HopperScript, which you can install for use on your Mac. The hidden font is located within the Resources folder of Aperture.

To get it, go to wherever Aperture 3 is installed, Control-click on Aperture, then select Show Package Contents from the pop-up menu. Navigate into Contents » Resources » Fonts, and there's the font! For faster access within the Resources folder, tap the F key, or if Aperture 3 is in your Applications folder, paste this in the Go To window in Finder: /Applications/Aperture.app/Contents/Resources/Fonts

[robg adds: I can confirm the font is there after installing Aperture 3.]

Since I'm lazy, I didn't want to bother actually installing Aperture to get my free font, I tried opening up the Aperture installation package with Pacifist (shareware, free to try) and found not only "Hopper Script" but also "Coolvetica" and "Cracked". I already seem to have the last one, but from Pacifist I could drag and drop the fonts right to my desktop.

Just open the install package in Pacifist, type "ttf" (without the quotes) in the search window, hit return, and you'll see Coolvetica and Hopper Script. Type "dfont" in the search window to get Cracked. Drag 'n' drop to a folder, then double-click to add to Font Book.
Thanks for the hint!

Interesting. I already had cracked, but not coolvetica. These two are part of the iLife slideshow options. It's possible that they're also included with other iLife apps as well, but I'm to lazy to check. Their installed location is /Library/Application Support/iLifeSlideshow/Fonts

I really doubt the fonts would expire after 30 days, because there is no DRM associated with fonts. Surprising that there is not, considering the top foundries' insane licensing deals and huge prices for freaking fonts, but you can freely copy fonts anywhere you like with no limitations.

BTW, what the hint is implying is to copy the fonts out of Aperture's bundle and install them via Font Book, or dropping them in appropriate Fonts folder.

Thanks,
I poorly wrote that, but I was actually questioning the legality of use of the font, after the trial runs out.
Since the font is incorporated in the app as part of a time limited trial and most likely comes under the same agreements of use as the trial app, I would expect it to be not quite legal to use it after the end of the 30 days.